Method and apparatus for local application server discovery in mobile edge computing

ABSTRACT

A method and apparatus for local application server discovery in edge computing. A method at a network node comprises determining whether one or more domain name system (DNS) servers in an edge computing of a network are available for a user equipment (UE) based on at least one of local configuration information, the UE&#39;s current location, the UE&#39;s capability or the UE&#39;s user subscription. The edge computing is close to the UE. The method further comprises in response to a positive determination, sending, to the UE, a first message including respective address of the one or more DNS servers in the edge computing of the network.

TECHNICAL FIELD

The non-limiting and exemplary embodiments of the present disclosuregenerally relate to the technical field of communications, andspecifically to methods and apparatuses for local application serverdiscovery in edge computing.

BACKGROUND

This section introduces aspects that may facilitate a betterunderstanding of the disclosure. Accordingly, the statements of thissection are to be read in this light and are not to be understood asadmissions about what is in the prior art or what is not in the priorart.

The DNS is a distributed directory that resolves human-readablehostnames or domain names into machine-readable addresses such as IPaddresses. In generally, the DNS server address of a user equipment (UE)may be configured manually or via a network device such as a packet datanetwork (PDN) gateway (PGW) or a session management function (SMF) or aUser Plane Function (UPF) or a dynamic host configuration protocol(DHCP) server, etc. When the DNS server address of the UE is configuredmanually, the user may configure it for example based on the user'spreference. When the DNS server address of the UE is configured ordiscovered via the network device, all the UEs configured by the networkdevice may get the same DNS configuration information.

Some networks/systems such as the fifth generation (5G) system cansupport a deployment of many applications and/or contents towards anedge (such as edge computing) of the network in a distributed manner toprovide low latency and huge data volume with high efficiency. Edgecomputing such as mobile edge computing (MEC) may be considered as onekey enabler to fulfill this kind of deployment. With the edge computing,the operators of the networks are able to host their own and/or thethird party applications and/or contents close to the user. The UE canaccess the application and/or content deployed in the edge computingclose to the user for example via (radio) access network ((R)AN) andlocally deployed user plane function (UPF), thus fulfilling theexpectations on the end to end user experience, and allowing the lowlatency to the edge applications and the heavy traffic to be offloadedfrom backbone network to the edge of the network.

5G system is able to support selective traffic routing to a data network(DN). For example, some selected traffic may be forwarded on an N6interface to the DN via a local UPF that may be “close” to the accessnetwork (AN) serving the UE, other traffic may be routed to the DN via a“central” UPF that may be deployed in a center of the network. Thesession management function (SMF) may control the data path of a packetdata unit (PDU) session so that the PDU session may simultaneouslycorrespond to multiple N6 interfaces.

In 5G system (5GS), to support the edge computing and its deployment,some enablers have been specified in 3rd Generation Partnership Project(3GPP), for example, local area data network (LADN), local access to aDN by locally deployed UPF (supporting uplink classifier (UL CL) orbranching point (BP)), user plane (re)selection, and AF (applicationfunction) influenced traffic routing.

Several solutions have been proposed for discussion in 3GPP but noagreement can be reached, for example, redirecting DNS query request toa local DNS server in the edge of the network, modifying information(e.g. server address) in the DNS response, or modifying a destination IPaddress of user traffic flow.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

There are some issues that were raised during the initial 5GS work (e.g.Internet protocol (IP) discovery for local application server forexample deployed in the MEC, support for seamless application migration,etc.), but not fully addressed in current specification of 3GPP.

Before an introduction of the MEC service, a serving DNS server candiscovery a static and unique application server for a user of a UE,regardless of mobility of the UE. The DNS resolution process may onlyneed to be queried from pre-registered information. However, when theMEC service is introduced, the application servers can be deployed atthe edge of the network. There may be multiple instances of applicationserver corresponding to different IP addresses. Furthermore, for 5GMEC-based Content Distribution Networks (CDNs), the selection ofapplication servers subjects to change for example due to UE mobilityfrom a serving area of a MEC to another serving area of another MEC. Thediscovery of application server becomes too complicated to be resolvedby a current DNS discovery mechanism.

As described in the above, some solutions have been discussed in 3GPP,however these solutions violate a principle of request for comments(RFC) standards for DNS and potentially open users to cross-sitescripting attacks.

To overcome or mitigate at least one above mentioned problems or otherproblems or provide a useful solution, local application serverdiscovery in edge computing may be desirable.

In an embodiment, SMF can send an address of local DNS Server (LDNS) ina MEC platform to a UE if MEC is available for the UE's location. The UEmay update its IP configuration with the received address of LDNS. TheUE can map different applications to different DNS servers (Remote DNSserver or local DNS server). In this way of dynamic DNS addressconfiguration, the UE can query and discover the IP address of the localapplication servers (AS) in the edge of the network.

In an embodiment, the SMF may only send the UE the address of LDNS. TheUE can replace the address of its old DNS server with the address ofLDNS, which means that all DNS queries in the PDU session will be sentto the LDNS. In this case, LDNS can support the capability of DNSrecursive or forwarding DNS queries to central DNS server, when therequested application server is not available in the MEC platform.

In an embodiment, the SMF can send the addresses of multiple DNS servers(e.g. LDNS as primary and central DNS server as backup) to the UE.

In a first aspect of the disclosure, there is provided a method at anetwork node. The method comprises determining whether one or moredomain name system (DNS) servers in an edge computing of a network areavailable for a user equipment (UE) based on at least one of localconfiguration information, the UE's current location, the UE'scapability or the UE's user subscription. The edge computing is close tothe UE. The method further comprises in response to a positivedetermination, sending, to the UE, a first message including respectiveaddress of the one or more DNS servers in the edge computing of thenetwork.

In an embodiment, the step of determining may be in response to aconfiguration update initiated by the network.

In an embodiment, the method may further comprise receiving, from theUE, a DNS server address request. The step of determining may be inresponse to receiving the DNS server address request.

In an embodiment, the DNS server address request may indicate that theUE requests the one or more DNS servers in the edge computing of thenetwork.

In an embodiment, the DNS server address request may be an Internetprotocol (IP) version 4 and/or version 6 DNS server address request.

In an embodiment, the DNS server address request and the respectiveaddress of the one or more DNS servers may be included in extendedprotocol configuration options (PCO) during a packet data network (PDN)connection establishment procedure or a protocol data unit (PDU) sessionestablishment procedure.

In an embodiment, the DNS server address request may be included in adynamic host configuration protocol (DHCP) discovery message.

In an embodiment, the first message may include only the respectiveaddress of one or more DNS servers in the edge computing of the network.

In an embodiment, the first message may include the respective addressof one or more DNS servers in the edge computing of the network andrespective address of one or more other DNS servers.

In an embodiment, the respective address of one or more DNS servers inthe edge computing of the network included in the first message may havean indication that the one or more DNS servers are in the edge computingof network.

In an embodiment, the method may further comprise in response to anegative determination, sending, to the UE, a second message includingrespective address of one or more other DNS servers.

In an embodiment, the DNS server addresses included in the first messagemay be listed in order of preference such that the one or more DNSservers in the edge computing of the network are selected for DNS queryby the UE at first.

In an embodiment, a rule of DNS address selection may be delivered tothe UE such that the one or more DNS servers in the edge computing ofthe network are selected for DNS query by the UE at first.

In an embodiment, the first message may be a protocol data unit (PDU)session establishment accept message or an activate default EPS bearercontext request.

In an embodiment, the method may further comprise deciding whethercurrent DNS server information for the UE needs to be changed based onat least one of local configuration information, the UE's currentlocation, the UE's capability or the UE's user subscription. The methodmay further comprise when the current DNS server information for the UEneeds to be changed, sending a third message including updated DNSserver information to the UE.

In an embodiment, the updated DNS server information may includerespective address of one or more DNS servers in another edge computingof the network. Said another edge computing may be close to the UE.

In an embodiment, the updated DNS server information may be included inextended protocol configuration options (PCO) during a protocol dataunit (PDU) session modification procedure or a packet data networkgateway (PGW) initiated bearer modification procedure.

In an embodiment, the third message may be a protocol data unit (PDU)session modification command message or modify evolved packet system(EPS) bearer context request.

In an embodiment, at least one application and/or content may bedeployed towards the edge computing of the network in a distributedmanner.

In an embodiment, the network node may be a packet data network (PDN)gateway or session management function (SMF).

In a second aspect of the disclosure, there is provided a method at auser equipment (UE). The method comprises receiving, from a networknode, a first message including respective address of the one or moredomain name system (DNS) servers in an edge computing of a network. Theone or more DNS servers in the edge computing of the network aredetermined to be available for the UE based on at least one of localconfiguration information, the UE's current location, the UE'scapability or the UE's user subscription, and the edge computing isclose to the UE. The method further comprises using at least one DNSserver address included in the first message for DNS query.

In an embodiment, the step of receiving may be in response to aconfiguration update initiated by the network.

In an embodiment, the method may further comprise sending, to thenetwork mode, a DNS server address request. The step of receiving may bein response to sending the DNS server address request.

In an embodiment, the method may further comprise receiving, from thenetwork node, a second message including respective address of one ormore other DNS servers. The one or more DNS servers in the edgecomputing of the network are determined to not available for the UEbased on at least one of local configuration information, the UE'scurrent location, the UE's capability or the UE's user subscription. themethod may further comprise using the respective address of one or moreother DNS servers for DNS query.

In an embodiment, the method may further comprise receiving a thirdmessage including updated DNS server information from the network node.The method may further comprise using the updated DNS server informationfor DNS query.

In a third aspect of the disclosure, there is provided an apparatus atnetwork node. The apparatus comprises a processor; and a memory coupledto the processor, said memory containing instructions executable by saidprocessor, whereby said apparatus is operative to determine whether oneor more domain name system (DNS) servers in an edge computing of anetwork are available for a user equipment (UE) based on at least one oflocal configuration information, the UE's current location, the UE'scapability or the UE's user subscription. The edge computing is close tothe UE. Said apparatus is further operative to in response to a positivedetermination, send, to the UE, a first message including respectiveaddress of the one or more DNS servers in the edge computing of thenetwork.

In a fourth aspect of the disclosure, there is provided an apparatus ata user equipment (UE). The apparatus comprises a processor; and a memorycoupled to the processor, said memory containing instructions executableby said processor, whereby said apparatus is operative to receive, froma network node, a first message including respective address of the oneor more domain name system (DNS) servers in an edge computing of anetwork, wherein the one or more DNS servers in the edge computing ofthe network are determined to be available for the UE based on at leastone of local configuration information, the UE's current location, theUE's capability or the UE's user subscription, and the edge computing isclose to the UE. Said apparatus is further operative to use at least oneDNS server address included in the first message for DNS query.

In a fifth aspect of the disclosure, there is provided a network node.The network node comprises a determining module and an sending module.The determining module may be configured to determine whether one ormore domain name system (DNS) servers in an edge computing of a networkare available for a user equipment (UE) based on at least one of localconfiguration information, the UE's current location, the UE'scapability or the UE's user subscription, wherein the edge computing isclose to the UE. The sending module may be configured to send, to theUE, a first message including respective address of the one or more DNSservers in the edge computing of the network in response to a positivedetermination.

In a sixth aspect of the disclosure, there is provided a UE. The UEcomprises a receiving module and a using module. The receiving modulemay be configured to receive, from a network node, a first messageincluding respective address of the one or more domain name system (DNS)servers in an edge computing of a network. The one or more DNS serversin the edge computing of the network are determined to be available forthe UE based on at least one of local configuration information, theUE's current location, the UE's capability or the UE's usersubscription, and the edge computing is close to the UE. The usingmodule may be configured to use at least one DNS server address includedin the first message for DNS query.

In another aspect of the disclosure, there is provided a computerprogram product comprising instructions which, when executed on at leastone processor, cause the at least one processor to carry out the methodaccording to the first aspect of the disclosure.

In another aspect of the disclosure, there is provided a computerprogram product comprising instructions which, when executed on at leastone processor, cause the at least one processor to carry out the methodaccording to the second aspect of the disclosure.

In another aspect of the disclosure, there is provided acomputer-readable storage medium storing instructions which, whenexecuted on at least one processor, cause the at least one processor tocarry out the method according to the first aspect of the disclosure.

In another aspect of the disclosure, there is provided acomputer-readable storage medium storing instructions which, whenexecuted on at least one processor, cause the at least one processor tocarry out the method according to the second aspect of the disclosure.

Many advantages may be achieved by applying the proposed solutionaccording to embodiments of the present disclosure. For example, someembodiments of the disclosure may provide a method of successfuldiscovery of application server address that is “close” to the UE via amethod of dynamic configuration of DNS address in the UE. Someembodiments of the disclosure may can resolve the problem of MEC trafficrouting in the 5G system. Some embodiments of the disclosure maymaintain the consistence of standardized DNS discovery procedures andthe integrity of user DNS messages. Some embodiments of the disclosurecan avoid the security risk of DNS hijacking and IP packet modification.In some embodiments of the disclosure, more security extension (forexample: HTTPS (Hypertext Transfer Protocol Secure), DNSSEC (Domain NameSystem Security Extensions) etc.) can be supported in the solution. Someembodiments of the disclosure can be based on standardized 5G signalingprocedures (e.g. PDU Session establishment, PDU Session Modificationetc.) with the enhancement of dynamic DNS address configuration in theUE. Some embodiments of the disclosure can be realized via simplemodification to the information elements of related NAS messages. Someembodiments of the disclosure can minimize the impact to the 5G system,no modification requirement to the User Plane Function (UPF). Someembodiments of the disclosure can resolve the problem of IP addressdiscovery of application servers in the MEC via a method of dynamicconfiguration of DNS address in the UE. In some embodiments of thedisclosure, the SMF can update the IP configuration in the UE, e.g.address of Local DNS (LDNS), when the new PSA UPF connecting to the MECwas established. Some embodiments of the disclosure propose single DNSaddress in the UE. Some embodiments of the disclosure propose multipleDNS addresses in the UE. In some embodiments of the disclosure, the UEcan easily discover the local AS via the LDNS server in the MEC, andselected traffic may be forwarded to the AS that is “close” to the UE.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and benefits of variousembodiments of the present disclosure will become more fully apparent,by way of example, from the following detailed description withreference to the accompanying drawings, in which like reference numeralsor letters are used to designate like or equivalent elements. Thedrawings are illustrated for facilitating better understanding of theembodiments of the disclosure and not necessarily drawn to scale, inwhich:

FIG. 1 schematically shows a high level architecture in a 4G network;

FIG. 2 schematically shows a high level architecture in a 5G network;

FIG. 3 shows a flowchart of a method according to an embodiment of thepresent disclosure;

FIG. 4 shows a flowchart of a method according to another embodiment ofthe present disclosure;

FIG. 5 shows a flowchart of a method according to another embodiment ofthe present disclosure;

FIG. 6 shows a flowchart of a method according to another embodiment ofthe present disclosure;

FIG. 7 schematically shows IP address resolving procedure with singleDNS address configured in the UE;

FIG. 8 schematically shows IP address resolving procedure with multipleDNS address configured in the UE;

FIG. 9 shows a flowchart of a method according to an embodiment of thepresent disclosure;

FIG. 10 shows a flowchart of a method according to another embodiment ofthe present disclosure;

FIG. 11 shows a flowchart of a method according to another embodiment ofthe present disclosure;

FIG. 12 shows an example of distributed application servers in 5Gdeployment;

FIG. 13 shows a flowchart of a method according to another embodiment ofthe present disclosure;

FIG. 14 shows a flowchart of a method according to another embodiment ofthe present disclosure;

FIG. 15 is a block diagram showing an apparatus suitable for use inpracticing some embodiments of the disclosure;

FIG. 16 is a block diagram showing a network node according to anembodiment of the disclosure; and

FIG. 17 is a block diagram showing a UE according to an embodiment ofthe disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure are described in detail withreference to the accompanying drawings. It should be understood thatthese embodiments are discussed only for the purpose of enabling thoseskilled persons in the art to better understand and thus implement thepresent disclosure, rather than suggesting any limitations on the scopeof the present disclosure. Reference throughout this specification tofeatures, advantages, or similar language does not imply that all of thefeatures and advantages that may be realized with the present disclosureshould be or are in any single embodiment of the disclosure. Rather,language referring to the features and advantages is understood to meanthat a specific feature, advantage, or characteristic described inconnection with an embodiment is included in at least one embodiment ofthe present disclosure. Furthermore, the described features, advantages,and characteristics of the disclosure may be combined in any suitablemanner in one or more embodiments. One skilled in the relevant art willrecognize that the disclosure may be practiced without one or more ofthe specific features or advantages of a particular embodiment. In otherinstances, additional features and advantages may be recognized incertain embodiments that may not be present in all embodiments of thedisclosure.

As used herein, the term “network” refers to a network following anysuitable wireless communication standards such as new radio (NR), longterm evolution (LTE), LTE-Advanced, wideband code division multipleaccess (WCDMA), high-speed packet access (HSPA), Code Division MultipleAccess (CDMA), Time Division Multiple Address (TDMA), Frequency DivisionMultiple Access (FDMA), Orthogonal Frequency-Division Multiple Access(OFDMA), Single carrier frequency division multiple access (SC-FDMA) andother wireless networks. A CDMA network may implement a radio technologysuch as Universal Terrestrial Radio Access (UTRA), etc. UTRA includesWCDMA and other variants of CDMA. A TDMA network may implement a radiotechnology such as Global System for Mobile Communications (GSM). AnOFDMA network may implement a radio technology such as Evolved UTRA(E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDMA, Ad-hoc network, wireless sensornetwork, etc. In the following description, the terms “network” and“system” can be used interchangeably. Furthermore, the communicationsbetween two devices in the network may be performed according to anysuitable communication protocols, including, but not limited to, thecommunication protocols as defined by a standard organization such as3GPP. For example, the communication protocols as may comprise the firstgeneration (1G), 2G, 3G, 4G, 4.5G, 5G communication protocols, and/orany other protocols either currently known or to be developed in thefuture.

The term “network entity” or “network node” as used herein refers to anetwork device (physical or virtual) in a communication network. In CUPS(Control User Plane Split) architecture, the network node may comprise acontrol plane function and a user plane function. The network device mayoffer numerous services to customers who are interconnected by an accessnetwork device. Each access network device is connectable to a corenetwork device over a wired or wireless connection.

The term “network function (NF)” refers to any suitable function whichcan be implemented in a network node (physical or virtual) of acommunication network. For example, the 5G system (5GS) may comprise aplurality of NFs such as AMF (Access and mobility Function), SMF(Session Management Function), AUSF (Authentication Service Function),UDM (Unified Data Management), PCF (Policy Control Function), AF(Application Function), NEF (Network Exposure Function), UPF (User planeFunction) and NRF (NF Repository Function), (R)AN ((radio) accessnetwork), SCP (service communication proxy), etc. In other embodiments,the network function may comprise different types of NFs for exampledepending on a specific type of network.

The term “terminal device” refers to any end device that can access acommunication network and receive services therefrom. By way of exampleand not limitation, the terminal device refers to a mobile terminal,user equipment (UE), or other suitable devices. The UE may be, forexample, a Subscriber Station (SS), a Portable Subscriber Station, aMobile Station (MS), or an Access Terminal (AT). The terminal device mayinclude, but not limited to, a portable computer, an image captureterminal device such as a digital camera, a gaming terminal device, amusic storage and a playback appliance, a mobile phone, a cellularphone, a smart phone, a voice over IP (VoIP) phone, a wireless localloop phone, a tablet, a wearable device, a personal digital assistant(PDA), a portable computer, a desktop computer, a wearable terminaldevice, a vehicle-mounted wireless terminal device, a wireless endpoint,a mobile station, a laptop-embedded equipment (LEE), a laptop-mountedequipment (LME), a USB dongle, a smart device, a wirelesscustomer-premises equipment (CPE) and the like. In the followingdescription, the terms “terminal device”, “terminal”, “user equipment”and “UE” may be used interchangeably. As one example, a terminal devicemay represent a UE configured for communication in accordance with oneor more communication standards promulgated by the 3GPP, such as 3GPP′LTE standard or NR standard. As used herein, a “user equipment” or “UE”may not necessarily have a “user” in the sense of a human user who ownsand/or operates the relevant device. In some embodiments, a terminaldevice may be configured to transmit and/or receive information withoutdirect human interaction. For instance, a terminal device may bedesigned to transmit information to a network on a predeterminedschedule, when triggered by an internal or external event, or inresponse to requests from the communication network. Instead, a UE mayrepresent a device that is intended for sale to, or operation by, ahuman user but that may not initially be associated with a specifichuman user.

As yet another example, in an Internet of Things (TOT) scenario, aterminal device may represent a machine or other device that performsmonitoring and/or measurements, and transmits the results of suchmonitoring and/or measurements to another terminal device and/or networkequipment. The terminal device may in this case be a machine-to-machine(M2M) device, which may in a 3GPP context be referred to as amachine-type communication (MTC) device. As one particular example, theterminal device may be a UE implementing the 3GPP narrow band internetof things (NB-IoT) standard. Particular examples of such machines ordevices are sensors, metering devices such as power meters, industrialmachinery, or home or personal appliances, for example refrigerators,televisions, personal wearables such as watches etc. In other scenarios,a terminal device may represent a vehicle or other equipment that iscapable of monitoring and/or reporting on its operational status orother functions associated with its operation.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” and the like indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but it is not necessary that every embodiment includesthe particular feature, structure, or characteristic. Moreover, suchphrases are not necessarily referring to the same embodiment. Further,when a particular feature, structure, or characteristic is described inconnection with an embodiment, it is submitted that it is within theknowledge of one skilled in the art to affect such feature, structure,or characteristic in connection with other embodiments whether or notexplicitly described.

It shall be understood that although the terms “first” and “second” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and similarly, a second element could be termed a firstelement, without departing from the scope of example embodiments. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed terms.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises”, “comprising”, “has”, “having”, “includes” and/or“including”, when used herein, specify the presence of stated features,elements, and/or components etc., but do not preclude the presence oraddition of one or more other features, elements, components and/orcombinations thereof.

It is noted that these terms as used in this document are used only forease of description and differentiation among nodes, devices or networksetc. With the development of the technology, other terms with thesimilar/same meanings may also be used.

In the following description and claims, unless defined otherwise, alltechnical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skills in the art to which thisdisclosure belongs.

Although the subject matter described herein may be implemented in anyappropriate type of system using any suitable components, theembodiments disclosed herein are described in relation to acommunication system complied with the exemplary system architecture asillustrated in clause 4.2 of 3GPP TS23.501 V16.1.0 and clause 4.2 of3GPP TS 23.401 V16.3.0, the disclosure of which is incorporated byreference herein in its entirety. For simplicity, the systemarchitectures of FIGS. 1-2 only depict some exemplary elements ofexemplary system architectures. In practice, a communication system mayfurther include any additional elements suitable to supportcommunication between terminal devices or between a wireless device andanother communication device, such as a landline telephone, a serviceprovider, or any other network node or terminal device. Thecommunication system may provide communication and various types ofservices to one or more terminal devices to facilitate the terminaldevices' access to and/or use of the services provided by, or via, thecommunication system.

FIG. 1 schematically shows a high level architecture in a 4G network.The functional description of the entities and the description ofreference points as shown in FIG. 1 are specified in 3GPP TS 23.401V16.3.0. FIG. 1 only depicts some exemplary elements such as universalterrestrial radio access network (UTRAN), Global System for MobileCommunications (GSM)/Enhanced Data for GSM Evolution (EDGE) Radio AccessNetwork (GERAN), serving general packet radio service support node(SGSN), mobility management entity (MME), Policy and Charging RulesFunction (PCRF), home subscriber server (HSS), UE, evolved universalterrestrial radio access network (E-UTRAN), Serving gateway (SGW), PDNgateway (PGW), etc. In practice, a communication system may furtherinclude any additional elements suitable to support communicationbetween terminal devices or between a wireless device and anothercommunication device, such as a landline telephone, a service provider,or any other network node or terminal device. The communication systemmay provide communication and various types of services to one or moreterminal devices to facilitate the terminal devices' access to and/oruse of the services provided by, or via, the communication system.

The PGW is the gateway which terminates the SGi interface towards thePDN. The PGW functions may include for both the GTP-based and thePMIP-based S5/S8:

-   -   UE IP address allocation;    -   DHCPv4 (server and client) and DHCPv6 (client and server)        functions;    -   etc.

FIG. 2 schematically shows a high level architecture in a 5G network.The system architecture of FIG. 2 may comprise some exemplary elementssuch as AUSF, AMF, DN, NEF, NRF, NSSF, PCF, SMF, UDM, UPF, SCP, AF, UE,(R)AN.

In accordance with an exemplary embodiment, the UE can establish asignaling connection with the AMF over the reference point N1, asillustrated in FIG. 2. This signaling connection may enable NAS(Non-access stratum) signaling exchange between the UE and the corenetwork, comprising a signaling connection between the UE and the (R)ANand the N2 connection for this UE between the (R)AN and the AMT. The(R)AN can communicate with the UPF over the reference point N3. The UEcan establish a packet data unit (PDU) session to the DN (data network,e.g. an operator network or Internet) through the UPF over the referencepoint N6.

As further illustrated in FIG. 2, the exemplary system architecture alsocontains the service-based interfaces such as Nnrf, Nnef, Nausf, Nudm,Npcf, Namf and Nsmf exhibited by NFs such as the NRF, the NEF, the AUSF,the UDM, the PCF, the AMF and the SMF. In addition, FIG. 2 also showssome reference points such as N1, N2, N3, N4, N6 and N9, which cansupport the interactions between NF services in the NFs. For example,these reference points may be realized through corresponding NFservice-based interfaces and by specifying some NF service consumers andproviders as well as their interactions in order to perform a particularsystem procedure.

Various NFs shown in FIG. 2 may be responsible for functions such assession management, mobility management, authentication, and security.These may be critical for delivering a service in the network. The AUSF,AMF, DN, NEF, NRF, NSSF, PCF, SMF, UDM, UPF, AF, UE, SCP, (R)AN mayinclude the functionality for example as defined in clause 6.2 of 3GPPTS23.501 V16.1.0. For example, the SMF may include the followingfunctionalities:

-   -   Session Management e.g. Session Establishment, modify and        release, including tunnel maintain between UPF and AN node;    -   UE IP address allocation & management (including optional        Authorization). The UE IP address may be received from a UPF or        from an external data network;    -   DHCPv4 (server and client) and DHCPv6 (server and client)        functions;    -   Configures traffic steering at UPF to route traffic to proper        destination;    -   etc.

FIG. 3 shows a flowchart of a method according to an embodiment of thepresent disclosure, which may be performed by an apparatus implementedin/at or communicatively coupled to a network node. As such, theapparatus may provide means or modules for accomplishing various partsof the method 300 as well as means or modules for accomplishing otherprocesses in conjunction with other components. The network node can beany suitable network node such as PGW or SMF as shown in FIGS. 1-2,which can send the address of at least one DNS to a UE.

At block 302, the network node determines whether one or more DNSservers in an edge computing of a network are available for a userequipment (UE) based on at least one of local configuration information,the UE's current location, the UE's capability or the UE's usersubscription. The edge computing is close to the UE.

As used herein, a principle of the edge computing may be to extend cloudcomputing capabilities to the edge of the network. The edge computingmay minimize network congestion and/or improve resource optimization,user experience and overall performance of the network. The edgecomputing may provide a platform that provides cloud-computingcapabilities within edge devices of the network in close proximity tothe UEs. For example, the edge computing can use edge devices such asserver, User Plane Functions (UPF) or base stations for offloadingcomputation tasks from mobile devices. The edge computing can supportmany applications and contents that need to be deployed towards the edgeof the network in a distributed manner. With edge computing, theoperators are able to host their own and/or 3rd party applicationsand/or contents close to the user. The UE can access the applicationand/or content in the edge computing via an access network, thusfulfilling the expectations on the end to end user experience, andallowing the low latency to the edge applications and the heavy trafficto be offloaded from backbone network to the edge. The edge device canbe any suitable device such as User Plane Functions (UPF) or server orbase stations deployed in the edge of the network. Some edge computingparadigms may comprise mobile edge computing (MEC), fog computing, etc.Current efforts in the 3GPP SA2 standardization group are placed on“Study on enhancement of support for Edge Computing in 5GC (FS_enh_EC)”.In an embodiment, the edge computing as used herein may be similar tothe Edge Computing as described in 3GPP SA2 standardization group orclause 5.13 of 3GPP TS23.501 V16.1.0.

The network device can be triggered to determine whether one or more DNSservers in the edge computing of the network are available for the UEbased on at least one of local configuration information, the UE'scurrent location, the UE's capability or the UE's user subscription invarious ways. For example, this determination may be in response to thenetwork device receiving a request (such as a DHCP request or a DNSserver address request) from the UE or a command from another networkdevice or various events (such as a change of the UE's current locationand/or a change of the UE's capability and/or a change of the UE's usersubscription and/or a new edge computing has been deployed in thenetwork and/or an edge computing is failed or to be maintained or to bechanged to a sleeping state, etc.).

In an embodiment, the network device may determine whether one or moreDNS servers in the edge computing of the network are available for theUE based on the local configuration information. The locationconfiguration information may be related to the edge computing of thenetwork. For example, the location configuration information mayindicate that the network node has an associated edge computing, andthen the network device may determine whether one or more DNS servers inthe associated edge computing are available for the UE. When thelocation configuration information indicates that the network node doesnot have an associated edge computing, the network device may determineone or more other DNS servers for the UE.

In an embodiment, the network device may determine whether one or moreDNS servers in the edge computing of the network are available for theUE based on the UE's current location. For example, the network devicemay try to find an edge computing close to the UE by comparing the UE'scurrent location and one or more candidate edge computing's location anddetermine whether one or more DNS servers in the edge computing of thenetwork are available for the UE. When the network device does not findthe edge computing close to the UE, the network device may determine oneor more other DNS servers for the UE. The UE's current location can beobtained by the network device in various ways. For example, when thenetwork node such as SMF or PGW receives a packet data network (PDN)Connectivity Request or a protocol data unit (PDU) session establishmentrequest, the network node may obtain the UE's current location from thePDN Connectivity Request or the PDU session establishment request. Inaddition, the network node may obtain the UE's current location by usingvarious location service procedures for example as defined in various3GPP specifications. For example, when the network device is SMF, it canobtain the UE's current location by requesting location information forthe UE from AMF or requesting or subscribing the current geodetic andoptionally civic location of the UE from LMF (Location ManagementFunction).

In an embodiment, the network device may determine whether one or moreDNS servers in the edge computing of the network are available for theUE based on the UE's capability. For example, when the UE's capabilityindicates that the UE supports local DNS server (for example, DNS serverin the edge computing of the network), then the network device maydetermine whether one or more DNS servers in the edge computing of thenetwork are available for the UE. When the UE's capability does notexplicitly indicates that the UE support the local DNS server, thenetwork device may determine one or more DNS servers (local DNS orcentral DNS) for the UE. The UE's capability can be obtained by thenetwork device in various ways. For example, when the network node suchas SMF or PGW receives a packet data network (PDN) Connectivity Requestor a protocol data unit (PDU) session establishment request, it mayobtain the UE's capability from the PDN Connectivity Request or the PDUsession establishment request.

In an embodiment, the network device may determine whether one or moreDNS servers in the edge computing of the network are available for theUE based on the UE's user subscription. For example, when the UE'ssubscription indicates that the UE has subscribed to use local DNSserver (for example, DNS server in the edge computing of the network),then the network device may determine whether one or more DNS servers inthe edge computing of the network are available for the UE. When theUE's subscription indicates that the UE has not subscribed to use localDNS server, the network device may determine one or more other DNSservers for the UE. The UE's subscription can be obtained by the networkdevice in various ways such as from UDM/HS S.

In various embodiments, the edge computing may be close to the UE. Theterm “close” may means that the edge computing may be close to the UE interms of location, end to end latency, network topology, hop, etc.

In an embodiment, The network device may determine whether one or moreDNS servers in the edge computing of the network are available for theUE based on at least one of local configuration information, the UE'scurrent location, the UE's capability or the UE's user subscription inresponse to a configuration update initiated by the network. Theconfiguration update may be UE configuration update. For example, the UEconfiguration may be updated by the network at any time using UEconfiguration update procedure. In an embodiment, in 5GS, the UEconfiguration update procedure may be similar to the UE ConfigurationUpdate procedure as described in clause 4.2.4 of 3GPP TS 23.502 V16.1.1,the disclosure of which is incorporated by reference herein in itsentirety. In addition, a UE configuration update command sent from thenetwork node such as AMF may contain respective address of the one ormore DNS servers in the edge computing of the network.

At block 304, the network node sends, to the UE, a first messageincluding respective address of the one or more DNS servers in the edgecomputing of the network in response to a positive determination. Thefirst message may be any suitable message. For example, the message maybe a configuration update command message when the UE configurationupdate is initiated by the network. The message may be a DNS serveraddress response when the network node receives a DNS server addressrequest from the UE. The message may be a DHCP offer message when thenetwork node receives a DHCP discover message from the UE.

FIG. 4 shows a flowchart of a method according to another embodiment ofthe present disclosure, which may be performed by an apparatusimplemented in/at or communicatively coupled to a network node. As such,the apparatus may provide means or modules for accomplishing variousparts of the method 400 as well as means or modules for accomplishingother processes in conjunction with other components. The network nodecan be any suitable network node such as PGW or SW′ as shown in FIGS.1-2, which can send the address of at least one DNS to a UE. For someparts which have been described in the above embodiments, thedescription thereof is omitted here for brevity.

At block 402, the network node receives, from the UE, a DNS serveraddress request. The DNS server address request may be sent in variousways. For example, the DNS server address request may be sent during aPDN connection establishment procedure or a PDU session establishmentprocedure. For example, in 5GS, UE may initiate a PDU sessionestablishment procedure and send a PDU session establishment request toSMF. In the message, DNS Server IPv6 Address Request and/or DNS ServerIPv4 address Request may be indicated in extended PCO. In an embodiment,the term “PCO” may be similar to the PCO as described in 3GPPspecification such as 3GPP TS 23.502 V16.1.1.

In an embodiment, the DNS server address request may indicate that theUE requests the one or more DNS servers in the edge computing of thenetwork. When the network node receives this DNS server address request,it may provide respective address of the one or more DNS servers in theedge computing close to the UE of the network.

In an embodiment, the DNS server address request may be an Internetprotocol (IP) version 4 and/or version 6 DNS server address request.When the network node receives this DNS server address request, it mayprovide respective IPv4 address and/or IPv6 prefix of the one or moreDNS servers in the edge computing of the network.

In an embodiment, the DNS server address request and the respectiveaddress of the one or more DNS servers may be included in extendedprotocol configuration options (PCO) during a packet data network (PDN)connection establishment procedure as described 3GPP TS 23.401 V16.3.0or a protocol data unit (PDU) session establishment procedure asdescribed in clause 4.3.2.2.1 of 3GPP TS 23.502 V16.1.1.

In an embodiment, the DNS server address request may be included in adynamic host configuration protocol (DHCP) discovery message. The DHCPdiscovery message may be a DHCPv4 discovery message as described in RFC(Request For Comments) 2131 and/or DHCPv6 discovery message as describedin RFC 3736. In another embodiment, the DHCP discovery message mayfurther include the DNS server address request as described above. Forexample, to allocate the UE's IP address and send respective address ofthe one or more DNS servers in the edge computing of the network viaDHCPv4, the UE may indicate to the network node within the PCO that theUE requests to obtain the IPv4 address and respective address of the oneor more DNS servers in the edge computing of the network with DHCPv4.

Blocks 404 and 406 are similar to blocks 302 and 304 of FIG. 3.

In various embodiments, the first message may be a PDU sessionestablishment accept message as described in clause 4.3.2.2.1 of 3GPP TS23.502 V16.1.1 or an activate default EPS bearer context request asdescribed in 3GPP TS 23.401 V16.3.0.

In various embodiments, the first message sent by the network node mayinclude only the respective address of one or more DNS servers in theedge computing of the network. For example, when the UE has explicitlyrequested the respective address of one or more DNS servers in the edgecomputing of the network and/or when network node determines that two ormore DNS servers in an edge computing of a network are available for theUE and/or the UE supports the DNS servers in the edge computing of thenetwork and/or the UE has subscribed to use the DNS servers in the edgecomputing of the network, etc., then the network node may send only therespective address of one or more DNS servers in the edge computing ofthe network.

In various embodiments, the first message sent by the network node mayinclude the respective address of one or more DNS servers in the edgecomputing of the network and respective address of one or more other DNSservers. For example, when the UE has not explicitly requested therespective address of one or more DNS servers in the edge computing ofthe network and/or when network node determines that only one DNS serverin the edge computing of the network are available for the UE, etc.,then the network node may send respective address of one or more DNSservers in the edge computing of the network and respective address ofone or more other DNS servers. The one or more other DNS servers may beDNS servers in the center (such as cloud computing) of the network orother edge computing.

In various embodiments, the respective address of one or more DNSservers in the edge computing of the network included in the firstmessage has an indication that the one or more DNS servers are in theedge computing of network. The indication can be implemented in variousways. For example, the address of each DNS server may have an indicationsuch as a bit or bitmap.

At block 408, the network node sends, to the UE, a second messageincluding respective address of one or more other DNS servers inresponse to a negative determination. The second message may be similarto the first message except that the included address of DNS server. Forexample, when the network node determines that no DNS server in the edgecomputing of the network is available for the UE, the network node maysend, to the UE, a second message including respective address of one ormore other DNS servers. The one or more other DNS servers may be DNSservers in the center (such as cloud computing) of the network or otheredge computing.

In various embodiments, the DNS server addresses included in the firstmessage are listed in order of preference such that the one or more DNSservers in the edge computing of the network are selected for DNS queryby the UE at first. The network node and the UE may know the order ofpreference.

In various embodiments, a rule of DNS address selection may be deliveredto the UE such that the one or more DNS servers in the edge computing ofthe network are selected for DNS query by the UE at first.

FIG. 5 shows a flowchart of a method according to another embodiment ofthe present disclosure, which may be performed by an apparatusimplemented in/at or communicatively coupled to a network node. As such,the apparatus may provide means or modules for accomplishing variousparts of the method 500 as well as means or modules for accomplishingother processes in conjunction with other components. The network nodecan be any suitable network node such as PGW or SMF as shown in FIGS.1-2, which can send the address of at least one DNS to a UE. For someparts which have been described in the above embodiments, thedescription thereof is omitted here for brevity.

At block 502, the network node decides whether current DNS serverinformation for the UE needs to be changed based on at least one oflocal configuration information, the UE's current location, the UE'scapability or the UE's user subscription. For example, the network nodemay determine whether one or more DNS servers in an edge computing ofthe network are available for the UE based on at least one of localconfiguration information, the UE's current location, the UE'scapability or the UE's user subscription as described above. Then thenetwork node may compare current DNS server information for the UE andnew determined DNS server information for the UE and decide the currentDNS server information for the UE needs to be changed when there is achange between the current DNS server information and the new determinedDNS server information. When there is no change between the current DNSserver information and the new determined DNS server information, thenetwork node may decide that the current DNS server information for theUE needs not to be changed.

At block 504, the network node sends a third message including updatedDNS server information to the UE when the current DNS server informationfor the UE needs to be changed. The third message can be any suitablemessage which can be sent from the network node to the UE, such as NASsignaling exchange between the UE and the network device.

In an embodiment, the updated DNS server information may includerespective address of one or more DNS servers in another edge computingclose to the UE of the network. In another embodiment, the updated DNSserver information may include only respective address of one or moreDNS servers in another edge computing close to the UE of the network. Instill another embodiment, the updated DNS server information may includerespective address of one or more DNS servers in another edge computingclose to the UE of the network and/or respective address of one or moreother DNS servers.

In an embodiment, the updated DNS server information may be included inextended PCO during a PDU session modification procedure or a packetdata network gateway (PGW) initiated bearer modification procedure. ThePDU session modification procedure may be similar to the PDU SessionModification procedure as described in clause 4.3.3 of 3GPP TS 23.502V16.1.1. The packet data network gateway (PGW) initiated bearermodification procedure may be similar to PDN GW initiated bearermodification procedure as described in clause 5.4.2 of 3GPP TS 23.401V16.3.0. In an embodiment, the third message may be a PDU sessionmodification command message as described in clause 4.3.3 of 3GPP TS23.502 V16.1.1 or modify evolved packet system (EPS) bearer contextrequest as described in clause 5.4.2 of 3GPP TS 23.401 V16.3.0.

In an embodiment, at least one application and/or content may bedeployed towards the edge computing of the network in a distributedmanner.

In an embodiment, the network node may be a packet data network (PDN)gateway or session management function (SMF).

FIG. 6 shows a flowchart of a method according to another embodiment ofthe present disclosure, which may be performed by an apparatusimplemented in/at or communicatively coupled to a UE. As such, theapparatus may provide means or modules for accomplishing various partsof the method 600 as well as means or modules for accomplishing otherprocesses in conjunction with other components. The network node can beany suitable network node such as UE as shown in FIGS. 1-2. For someparts which have been described in the above embodiments, thedescription thereof is omitted here for brevity.

At block 602, the UE receives, from a network node, a first messageincluding respective address of the one or more domain name system (DNS)servers in an edge computing of a network. The one or more DNS serversin the edge computing of the network may be determined to be availablefor the UE based on at least one of local configuration information, theUE's current location, the UE's capability or the UE's usersubscription. The edge computing is close to the UE. For example, thenetwork node such as SMF or PGW may determine the one or more DNSservers in the edge computing of the network at block 302 of FIG. 3 andsend the first message to UE at block 304 of FIG. 3, and then the UE mayreceive the first message.

In an embodiment, the UE may receive the first message in response to aconfiguration update initiated by the network as described above.

At block 604, the UE uses at least one DNS server address included inthe first message for DNS query.

FIG. 7 schematically shows IP address resolving procedure with singleDNS address configured in the UE.

The SMF may send the address of local DNS server (LDNS) to the UE via aNAS message. The UE may update its local IP configuration. Optionally,if the UE already has a DNS address, the UE may replace current DNSaddress with the received address of the LDNS server. Then UE may sendat least one or all DNS queries for the PDU session to the LDNS server.The LDNS server can resolve the address of local application server (AS)which is close to the UE. When the local application server is notavailable or the LDNS cannot resolve the IP address of the DNS query,the LDNS may forward the DNS query to a remote DNS (RDNS) in a centralnetwork or to a recursive DNS server in a public Internet.

At step 702, the UE has been configured with the DNS address of theLDNS. The UE sends a DNS query to LNDS.

At step 704 (optional), if the LDNS cannot resolve the IP address, orlocal AS not available, LDNS may forward the DNS query to the RDNS inthe central network.

At step 706 (optional), if the LDNS cannot resolve the IP address, orlocal AS not available, LDNS may turn to a DNS server in the Internet.

At step 708, the LDNS sends the IP address of the AS in an answer to theUE.

FIG. 8 schematically shows IP address resolving procedure with multipleDNS address configured in the UE.

The SMF sends the UE the address of LDNS server and the RDNS server viaNAS message. The UE updates its local IP configuration, and stores bothabove DNS addresses (LDNS and RDNS). The LDNS server may be selected forDNS query at first. When the LDNS cannot resolve the DNS query, the RDNSserver can be selected as a secondary choice. Application Function (AF)or 5G system may also deliver a rule of DNS address selection to the UEfor more efficient process of application server discovery.

At step 802, the UE has been configured with multiple DNS address (e.g.LDNS & RDNS). The UE sends a DNS query to LNDS at first.

At step 804, the LDNS delivers the DNS answer to the UE.

At step 806 (conditional), if the LDNS cannot resolve the IP address, orlocal AS not available. The UE may send a new DNS query to RDNS serversin the central network.

At step 808 (conditional), the RDNS delivers the DNS answer to the UE.

In various embodiment, the UE can be configured with different rules orpriority for the selection of initial DNS server, e.g. based onapplication identifier (ID) or network policy.

FIG. 9 shows a flowchart of a method according to an embodiment of thepresent disclosure, which may be performed by an apparatus implementedin/at or communicatively coupled to a UE. As such, the apparatus mayprovide means or modules for accomplishing various parts of the method900 as well as means or modules for accomplishing other processes inconjunction with other components. The network node can be any suitablenetwork node such as UE as shown in FIGS. 1-2. For some parts which havebeen described in the above embodiments, the description thereof isomitted here for brevity.

At block 902, the UE sends, to the network mode, a DNS server addressrequest. For example, the DNS server address request may be sent duringa PDN connection establishment procedure or a PDU session establishmentprocedure. For example, in 5GS, UE may initiate a PDU sessionestablishment procedure and send a PDU session establishment request toSMF. In the message, DNS Server IPv6 Address Request and/or DNS ServerIPv4 address Request may be indicated in extended PCO.

Blocks 904 and 906 are similar to blocks 602 and 604 of FIG. 6 exceptthat the UE receives the first message in response to sending the DNSserver address request.

In an embodiment, the DNS server address request may indicate that theUE requests the one or more DNS servers in the edge computing of thenetwork. When the network node receives this DNS server address request,it may provide respective address of the one or more DNS servers in theedge computing close to the UE of the network.

In an embodiment, the DNS server address request may be an Internetprotocol (IP) version 4 and/or version 6 DNS server address request.When the network node receives this DNS server address request, it mayprovide respective IPv4 address and/or IPv6 prefix of the one or moreDNS servers in the edge computing of the network.

In an embodiment, the DNS server address request and the respectiveaddress of the one or more DNS servers may be included in extendedprotocol configuration options (PCO) during a packet data network (PDN)connection establishment procedure or a protocol data unit (PDU) sessionestablishment procedure.

In an embodiment, the DNS server address request may be included in adynamic host configuration protocol (DHCP) discovery message.

In an embodiment, the first message may include only the respectiveaddress of one or more DNS servers in the edge computing of a network.

In an embodiment, the first message may include the respective addressof one or more DNS servers in the edge computing of the network andrespective address of one or more other DNS servers.

In an embodiment, the respective address of one or more DNS servers inthe edge computing of the network included in the first message may havean indication that the one or more DNS servers are in the edge computingof network.

FIG. 10 shows a flowchart of a method according to another embodiment ofthe present disclosure, which may be performed by an apparatusimplemented in/at or communicatively coupled to a UE. As such, theapparatus may provide means or modules for accomplishing various partsof the method 1000 as well as means or modules for accomplishing otherprocesses in conjunction with other components. The network node can beany suitable network node such as UE as shown in FIGS. 1-2. For someparts which have been described in the above embodiments, thedescription thereof is omitted here for brevity.

At block 1002, the UE receives, from the network node, a second messageincluding respective address of one or more other DNS servers. The oneor more DNS servers in the edge computing of the network are determinedto not available for the UE based on at least one of local configurationinformation, the UE's current location, the UE's capability or the UE'suser subscription. For example, the network node may send the secondmessage at block 408 of FIG. 4, and then the UE may receive the secondmessage.

At block 1004, the UE uses the respective address of one or more otherDNS servers for DNS query.

In an embodiment, the DNS server addresses included in the first messagemay be listed in order of preference such that the one or more DNSservers in the edge computing of the network are selected for DNS queryby the UE at first.

In an embodiment, a rule of DNS address selection may be delivered tothe UE such that the one or more DNS servers in the edge computing ofthe network are selected for DNS query by the UE at first.

In an embodiment, the first message may be a protocol data unit (PDU)session establishment accept message.

FIG. 11 shows a flowchart of a method according to another embodiment ofthe present disclosure, which may be performed by an apparatusimplemented in/at or communicatively coupled to a UE. As such, theapparatus may provide means or modules for accomplishing various partsof the method 1100 as well as means or modules for accomplishing otherprocesses in conjunction with other components. The network node can beany suitable network node such as UE as shown in FIGS. 1-2. For someparts which have been described in the above embodiments, thedescription thereof is omitted here for brevity.

At block 1102, the UE receives a third message including updated DNSserver information from the network node. For example, the network modemay send the third message at block 504 of FIG. 5, and then the UE mayreceive the third message.

At block 1104, the UE uses the updated DNS server information for DNSquery.

In an embodiment, the updated DNS server information may includerespective address of one or more DNS servers in another edge computingof the network, wherein said another edge computing is close to the UE.

In an embodiment, the updated DNS server information may be included inextended protocol configuration options (PCO) during a protocol dataunit (PDU) session modification procedure or a packet data networkgateway (PGW) initiated bearer modification procedure.

In an embodiment, the second message may be a protocol data unit (PDU)session modification command message or modify evolved packet system(EPS) bearer context request.

In an embodiment, at least one application and/or content may bedeployed towards the edge computing of the network in a distributedmanner.

In an embodiment, the network node may be a packet data network (PDN)gateway or session management function (SMF).

FIG. 12 shows an example of distributed application servers in 5Gdeployment. As shown in FIG. 12, due to UE mobility or new traffic flowdetection, the 5G Core Network can select a traffic to be routed to theapplications in a local data network (DN). The SMF may decide toestablish a new PDU Session Anchor (PSA) close to the UE and executesthe traffic steering from the UPF to the local data network via a N6interface. The insertion of a UPF with UL CL for IPv4 or “BranchingPoint (BP)” for IPv6 multi-homing in a data path of the PDU session isdecided and controlled by the SMF. The embodiments of the disclosure canresolve the problem of IP address discovery of application servers (AS)in MEC for the UE. The SMF can update the IP configuration of UE, e.g.local DNS server (LDNS) in the MEC. When the new PSA UPF to the local DNwas established for the PDU session. UE can discover the local AS viaquerying the LDNS server in MEC, and the selected traffic is forwardedon an N6 interface to the DN that is “close” to the AN (access network)serving the UE.

When the UE moves out of the serving area of the current local PSA UPF,the SMF may setup a new local PSA UPF and steer the traffic flows of thePDU session to the new application server. When the local PSA UPF is notavailable or required any more, the SMF may remove the additional PSAUPF for the PDU session. SMF may inform the UE to update theconfiguration of DNS address to a new LDNS or RDNS correspondingly.

The change of UE IP configuration (e.g. the change of IP address/prefix,DNS address) can be notified to the AF (via NEF), in case of the AF/NEFsubscribes to the event exposure of the PDU session. Based on thenotification from the SMF, the AF can trigger the migration of UEservice context between different Application Servers to improve theuser experience of service continuity.

FIG. 13 shows a flowchart of a method according to another embodiment ofthe present disclosure.

At step 1302, UE may initiate PDU session establishment procedure andsends PDU session establishment request to SMF. In the message, DNSServer IPv6 Address Request and/or DNS Server IPv4 address Request maybe indicated in the extended PCO.

At step 1304, if local DNS server is available for the UE, e.g., basedon local configuration and UE's location, SMF may send to UE the localDNS server information instead of remote DNS server information.

At step 1306, SMF may send PDU session establishment accept to UE. Inthe extended PCO of this message, DNS Server IPv6 Address and/or DNSServer IPv4 address may be included which indicate the local DNS serverif available or the remote DNS server.

At step 1308, UE moves to another location area. SMF gets the UE'slatest location information, e.g., during the mobility or servicerequest procedure.

At step 1310, SMF decides that, e.g., based on local configuration andUE's location, whether the current DNS server information for the UEneeds to be changed. SMF sends to the UE new DNS server information,i.e., remote DNS server or local DNS server information, when thecurrent DNS server information for the UE needs to be changed.

At step 1312, if the UE's DNS server information needs to be changed,SMF sends PDU session modification command to UE. In the extended PCO ofthis message, DNS Server IPv6 Address and/or DNS Server IPv4 address maybe included which may indicate the local DNS server if available or theremote DNS server.

At step 1314, the UE stores the new DNS server information.

At step 1316, the UE sends PDU session modification complete to SMF.

FIG. 14 shows a flowchart of a method according to an embodiment of thepresent disclosure.

At step 1402, UE initiates PDU session establishment procedure and sendsPDU session establishment request to SMF. In this message, if UEsupports local DNS server in PCO function, UE indicates local DNS ServerIPv6 address request and/or local DNS server IPv4 address request in theextended PCO.

At step 1404, if requested by UE and local DNS server is available forthe UE, e.g., based on local configuration and UE's location, SMFadditionally sends to UE the local DNS server information. SMF alsostores the information that UE supports local DNS server in PCOfunction.

At step 1406, SMF sends PDU session establishment accept to UE. In thismessage, if requested by UE and the local DNS server is available, localDNS server IPv6 address and/or local DNS server IPv4 address areincluded in extended PCO.

At step 1408, UE stores the local DNS Server information and uses it fordifferent applications based on application needs, i.e., someapplications are associated to the remote DNS server (provided in DNSserver IPv6 address and/or DNS server IPv4 Address in extended PCO) andsome applications to the local DNS server.

At step 1410, UE moves to another location area. SMF gets the UE'slatest location information, e.g., during the mobility or servicerequest procedure.

At step 1412, SMF decides that, e.g., based on local configuration andUE's location, the local DNS server information needs to be changed.

At step 1414, If UE supports local DNS server in PCO and local DNSserver information needs to be changed, SW′ sends PDU sessionmodification command to UE. In this message, local DNS server IPv6address and/or local DNS server IPv4 address are included in extendedPCO.

At step 1416, UE stores the new local DNS Server information and uses itfor applications based on application needs.

At step 1418, UE sends PDU session modification complete to SMF.

Some messages as shown in FIGS. 13-14 are similar to the correspondingmessages as described in 3GPP TS 23.502 V16.1.1 or other 3GPPspecifications.

Many advantages may be achieved by applying the proposed solutionaccording to embodiments of the present disclosure. For example, someembodiments of the disclosure may provide a method of successfuldiscovery of application server address that is “close” to the UE via amethod of dynamic configuration of DNS address in the UE. Someembodiments of the disclosure may can resolve the problem of MEC trafficrouting in the 5G system. Some embodiments of the disclosure maymaintain the consistence of standardized DNS discovery procedures andthe integrity of user DNS messages. Some embodiments of the disclosurecan avoid the security risk of DNS hijacking and IP packet modification.In some embodiments of the disclosure, more security extension (forexample: HTTPS (Hypertext Transfer Protocol Secure), DNSSEC (Domain NameSystem Security Extensions) etc.) can be supported in the solution. Someembodiments of the disclosure can be based on standardized 5G signalingprocedures (e.g. PDU Session establishment, PDU Session Modificationetc.) with the enhancement of dynamic DNS address configuration in theUE. Some embodiments of the disclosure can be realized via simplemodification to the information elements of related NAS messages. Someembodiments of the disclosure can minimize the impact to the 5G system,no modification requirement to the User Plane Function (UPF). Someembodiments of the disclosure can resolve the problem of IP addressdiscovery of application servers in the MEC via a method of dynamicconfiguration of DNS address in the UE. In some embodiments of thedisclosure, the SMF can update the IP configuration in the UE, e.g.address of Local DNS (LDNS), when the new PSA UPF connecting to the MECwas established. Some embodiments of the disclosure propose single DNSaddress in the UE. Some embodiments of the disclosure propose multipleDNS addresses in the UE. In some embodiments of the disclosure, the UEcan easily discover the local AS via the LDNS server in the MEC, andselected traffic may be forwarded to the AS that is “close” to the UE.

FIG. 15 is a block diagram showing an apparatus suitable for use inpracticing some embodiments of the disclosure. For example, any one ofthe network node (such as SMF or PGW) or the UE as described above maybe implemented through the apparatus 1500.

The apparatus 1500 comprises at least one processor 1521, such as a DP,and at least one MEM 1522 coupled to the processor 1521. The apparatus1520 may further comprise a transmitter TX and receiver RX 1523 coupledto the processor 1521. The MEM 1522 stores a PROG 1524. The PROG 1524may include instructions that, when executed on the associated processor1521, enable the apparatus 1520 to operate in accordance with theembodiments of the present disclosure. A combination of the at least oneprocessor 1521 and the at least one MEM 1522 may form processing means1525 adapted to implement various embodiments of the present disclosure.

Various embodiments of the present disclosure may be implemented bycomputer program executable by one or more of the processor 1521,software, firmware, hardware or in a combination thereof.

The MEM 1522 may be of any type suitable to the local technicalenvironment and may be implemented using any suitable data storagetechnology, such as semiconductor based memory devices, magnetic memorydevices and systems, optical memory devices and systems, fixed memoriesand removable memories, as non-limiting examples.

The processor 1521 may be of any type suitable to the local technicalenvironment, and may include one or more of general purpose computers,special purpose computers, microprocessors, digital signal processorsDSPs and processors based on multicore processor architecture, asnon-limiting examples.

FIG. 16 is a block diagram showing a network node according to anembodiment of the disclosure. As shown, the network node 1600 comprisesa determining module 1602 and an sending module 1604. The determiningmodule 1602 may be configured to determine whether one or more domainname system (DNS) servers in an edge computing of a network areavailable for a user equipment (UE) based on at least one of localconfiguration information, the UE's current location, the UE'scapability or the UE's user subscription, wherein the edge computing isclose to the UE. The sending module 1604 may be configured to send, tothe UE, a first message including respective address of the one or moreDNS servers in the edge computing of the network in response to apositive determination.

FIG. 17 is a block diagram showing a UE according to an embodiment ofthe disclosure. As shown, the UE 1700 comprises a receiving module 1702and a using module 1704. The receiving module 1702 may be configured toreceive, from a network node, a first message including respectiveaddress of the one or more domain name system (DNS) servers in an edgecomputing of a network. The one or more DNS servers in the edgecomputing of the network are determined to be available for the UE basedon at least one of local configuration information, the UE's currentlocation, the UE's capability or the UE's user subscription, and theedge computing is close to the UE. The using module 1704 may beconfigured to use at least one DNS server address included in the firstmessage for DNS query.

According to an aspect of the disclosure it is provided a computerprogram product being tangibly stored on a computer readable storagemedium and including instructions which, when executed on at least oneprocessor, cause the at least one processor to carry out any of themethods related to the network node as described above.

According to an aspect of the disclosure it is provided a computerprogram product being tangibly stored on a computer readable storagemedium and including instructions which, when executed on at least oneprocessor, cause the at least one processor to carry out any of themethods related to the UE as described above.

According to an aspect of the disclosure it is provided acomputer-readable storage medium storing instructions which whenexecuted by at least one processor, cause the at least one processor tocarry out any of the methods related to the network node as describedabove.

According to an aspect of the disclosure it is provided acomputer-readable storage medium storing instructions which whenexecuted by at least one processor, cause the at least one processor tocarry out any of the methods related to the UE as described above.

In addition, the present disclosure may also provide a carriercontaining the computer program as mentioned above, wherein the carrieris one of an electronic signal, optical signal, radio signal, orcomputer readable storage medium. The computer readable storage mediumcan be, for example, an optical compact disk or an electronic memorydevice like a RAM (random access memory), a ROM (read only memory),Flash memory, magnetic tape, CD-ROM, DVD, Blue-ray disc and the like.

The techniques described herein may be implemented by various means sothat an apparatus implementing one or more functions of a correspondingapparatus described with an embodiment comprises not only prior artmeans, but also means for implementing the one or more functions of thecorresponding apparatus described with the embodiment and it maycomprise separate means for each separate function, or means that may beconfigured to perform two or more functions. For example, thesetechniques may be implemented in hardware (one or more apparatuses),firmware (one or more apparatuses), software (one or more modules), orcombinations thereof. For a firmware or software, implementation may bemade through modules (e.g., procedures, functions, and so on) thatperform the functions described herein.

Exemplary embodiments herein have been described above with reference toblock diagrams and flowchart illustrations of methods and apparatuses.It will be understood that each block of the block diagrams andflowchart illustrations, and combinations of blocks in the blockdiagrams and flowchart illustrations, respectively, can be implementedby various means including computer program instructions. These computerprogram instructions may be loaded onto a general purpose computer,special purpose computer, or other programmable data processingapparatus to produce a machine, such that the instructions which executeon the computer or other programmable data processing apparatus createmeans for implementing the functions specified in the flowchart block orblocks.

Further, while operations are depicted in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results. Incertain circumstances, multitasking and parallel processing may beadvantageous. Likewise, while several specific implementation detailsare contained in the above discussions, these should not be construed aslimitations on the scope of the subject matter described herein, butrather as descriptions of features that may be specific to particularembodiments. Certain features that are described in the context ofseparate embodiments may also be implemented in combination in a singleembodiment. Conversely, various features that are described in thecontext of a single embodiment may also be implemented in multipleembodiments separately or in any suitable sub-combination.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyimplementation or of what may be claimed, but rather as descriptions offeatures that may be specific to particular embodiments of particularimplementations. Certain features that are described in thisspecification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable sub-combination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a sub-combination or variation of a sub-combination.

It will be obvious to a person skilled in the art that, as thetechnology advances, the inventive concept can be implemented in variousways. The above described embodiments are given for describing ratherthan limiting the disclosure, and it is to be understood thatmodifications and variations may be resorted to without departing fromthe spirit and scope of the disclosure as those skilled in the artreadily understand. Such modifications and variations are considered tobe within the scope of the disclosure and the appended claims. Theprotection scope of the disclosure is defined by the accompanyingclaims.

1. A method at a network node, comprising: determining whether one ormore local domain name system (DNS) servers for edge computing areavailable for a user equipment (UE) based on at least one of localconfiguration information, UE's current location, and UE's capability orUE's user subscription; in response to a positive determination,sending, to the UE, a first message to establish a protocol data unit(PDU) session, wherein the first message including respective address ofthe one or more local DNS servers for edge computing; deciding whethercurrent local DNS server information for the UE needs to be changedbased on local configuration information or UE's mobility; and when thecurrent local DNS server information for the UE needs to be changed,sending another message to modify the PDU session, wherein the anothermessage includes updated DNS server information to the UE.
 2. The methodaccording to claim 1, wherein the determining is in response to aconfiguration update initiated by a network of the network node.
 3. Themethod according to claim 1, further comprising: receiving, from the UE,a DNS server address request, wherein the determining is in response toreceiving the DNS server address request.
 4. The method according toclaim 3, wherein the DNS server address request indicates that the UErequests the one or more local DNS servers in the edge computing of thenetwork.
 5. (canceled)
 6. The method according to claim 3, wherein theDNS server address request and the respective address of the one or morelocal DNS servers are included in extended protocol configurationoptions (PCO) during a packet data network (PDN) connectionestablishment procedure or a PDU session establishment procedure orwherein the DNS server address request is included in a dynamic hostconfiguration protocol (DHCP) discovery message. 7-8. (canceled)
 9. Themethod according to claim 1, wherein the first message includes therespective address of one or more local DNS servers in the edgecomputing of the network and respective address of one or more other DNSservers.
 10. The method according to claim 9, wherein the respectiveaddress of one or more local DNS servers in the edge computing of thenetwork included in the first message has an indication that the one ormore local DNS servers are in the edge computing of network.
 11. Themethod according to claim 1 further comprising: in response to anegative determination, sending, to the UE, a second message includingrespective address of one or more other DNS servers. 12-13. (canceled)14. The method according to claim 1, wherein the first message is a PDUsession establishment accept message or an activate default evolvedpacket system (EPS) bearer context request. 15-16. (canceled)
 17. Themethod according to claim 1, wherein the updated DNS server informationis included in extended protocol configuration options (PCO) during aPDU session modification procedure or a packet data network gateway(PGW) initiated bearer modification procedure; wherein the anothermessage is a PDU session modification command message or modify evolvedpacket system (EPS) bearer context request; or wherein the updated DNSserver information is included in the extended PCO during the PDUsession modification procedure or the PGW initiated bearer modificationprocedure, and wherein the another message is the PDU sessionmodification command message or the modify EPS bearer context request.18-19. (canceled)
 20. The method according to claim 1, wherein thenetwork node is a packet data network (PDN) gateway or sessionmanagement function (SMF).
 21. A method at a user equipment (UE),comprising: receiving, from a network node, a first message to establisha protocol data unit (PDU) session, wherein the first message includingrespective address of one or more local domain name system (DNS) serversfor edge computing, wherein the one or more local DNS servers aredetermined to be available for the UE based on at least one of localconfiguration information, UE's current location, and UE's capability orUE's user subscription; using the respective address of the one or morelocal DNS servers included in the first message for DNS query fordiscovery of local application server for edge computing; receivinganother message for modification of the PDU session, the another messageincluding updated local DNS server information from the network node;and using the updated local DNS server information for DNS query fordiscovery of local application server for edge computing, wherein theanother message is received in response to UE mobility or localconfiguration in the network node.
 22. The method according to claim 21,wherein the receiving is in response to a configuration update initiatedby a network of the network node.
 23. The method according to claim 21,further comprising: sending, to the network node, a DNS server addressrequest, wherein the receiving is in response to sending the DNS serveraddress request.
 24. The method according to claim 23, wherein the DNSserver address request indicates that the UE requests the one or morelocal DNS servers in the edge computing of the network.
 25. (canceled)26. The method according to claim 23, wherein the DNS server addressrequest and the respective address of the one or more local DNS serversare included in extended protocol configuration options (PCO) during apacket data network (PDN) connection establishment procedure or a PDUsession establishment procedure; or wherein the DNS server addressrequest is included in a dynamic host configuration protocol (DHCP)discovery message. 27-30. (canceled)
 31. The method according to claim21, further comprising: receiving, from the network node, a secondmessage including respective address of one or more other DNS servers,when the one or more local DNS servers in the edge computing of thenetwork are determined to not be available for the UE based on at leastone of local configuration information, the UE's current location, theUE's capability or the UE's user subscription; and using the respectiveaddress of one or more other DNS servers for DNS query. 32-33.(canceled)
 34. The method according to claim 21, wherein the firstmessage is a PDU session establishment accept message or an activatedefault evolved packet system (EPS) bearer context request. 35.(canceled)
 36. The method according to claim 21, wherein the updated DNSserver information includes respective address of one or more DNSservers in another edge computing of the network.
 37. The methodaccording to claim 21, wherein the updated DNS server information isincluded in extended protocol configuration options (PCO) during a PDUsession modification procedure or a packet data network gateway (PGW)initiated bearer modification procedure; wherein the another message isa PDU session modification command message or modify evolved packetsystem (EPS) bearer context request; or wherein the updated DNS serverinformation is included in the extended PCO during the PDU sessionmodification procedure or the PGW initiated bearer modificationprocedure, and wherein the another message is the PDU sessionmodification command message or the modify EPS bearer context request.38-40. (canceled)
 41. An apparatus at a network node, comprising: aprocessor; and a memory coupled to the processor, said memory (1522)containing instructions executable by said processor, wherein saidapparatus is to: determine whether one or more local domain name system(DNS) servers for edge computing are available for a user equipment (UE)based on at least one of local configuration information, UE's currentlocation, and UE's capability or UE's user subscription; in response toa positive determination, send, to the UE, a first message associated toestablish a protocol data unit (PDU) session, wherein the first messageincluding respective address of the one or more local DNS servers foredge computing; deciding whether current local DNS server informationfor the UE needs to be changed based on local configuration informationor UE's mobility; and when the current local DNS server information forthe UE needs to be changed, sending another message to modify the PDUsession, wherein the another message includes updated DNS serverinformation to the UE.
 42. (canceled)
 43. An apparatus at a userequipment (UE), comprising: a processor; and a memory coupled to theprocessor, said memory containing instructions executable by saidprocessor, wherein said apparatus is to: receive, from a network node, afirst message to establish a protocol data unit (PDU) session, whereinthe first message including respective address of one or more localdomain name system (DNS) servers for edge computing, wherein the one ormore local DNS servers are determined to be available for the UE basedon at least one of local configuration information, UE's currentlocation, and UE's capability or UE's user subscription; and use therespective address of the one or more local DNS servers included in thefirst message for DNS query for discovery of local application serverfor edge computing; receive another message for modification of the PDUsession, the another message including updated local DNS serverinformation from the network node; and using the updated local DNSserver information for DNS query for discovery of local applicationserver for edge computing, wherein the another message is received inresponse to UE mobility or local configuration in the network node.44-46. (canceled)